Centrifuge rotor and method of assembly

Abstract

A centrifuge rotor is claimed which comprises a rotor having a plurality of radially extending arms, having a construction to matably receive a pin structure within a recess formed in the upper surface of the rotor, to support the pin structure against loads generated by centrifugal force without stressing a fastener. In assembly, the pin structures permanently mount trunnions for receiving a sample container, for pivotal movement, in a manner such that the trunnion and sample container cooperate to resist stresses and deformation caused by centrifugal loads.

We claim: 
     
       1. A centrifuge rotor comprising: a rotor body having a plurality of longitudinal recesses formed into the peripheral surface of said rotor to receive sample containers, said recesses defining a plurality of extending radial arms, and having a latitudinal recess formed in the upper surface of said rotor body defining a substantially vertical, inwardly directed, support shoulder in the upper surface of each arm;   and a pin structure secured to said rotor by fastening means and matably shaped with said support shoulder along the upper surface of each arm of said rotor for assembly on said rotor to provide a pivotal mounting for a sample container which provides radial support against outward forces applied to said sample containers without stressing the fastening means.   
     
     
       2. The centrifuge rotor claimed in claim 1 additionally comprising a trunnion for receiving a sample container permanently mounted in assembly of said rotor, for pivotal movement along a radial line of said rotor. 
     
     
       3. The centrifuge rotor assembly claimed in claim 2 additionally comprising a sample container for matable insertion within a trunnion of said rotor assembly, said container and trunnion in assembly providing cooperating structural support against centrifugal loads placed on the pivotal mounting of said rotor for said sample container. 
     
     
       4. The rotor assembly of claim 3 wherein said trunnion provides a contact surface having a first angular relationship with a central longitudinal axis thereof, and said sample container providing a contact surface with a second dissimilar angular surface with a central axis thereof. 
     
     
       5. The centrifuge rotor of claim 1 wherein said latitudinal recess is a circular recess formed in an upper surface of said rotor and further defines a floor surface, the circular recess and floor surface matably receiving an outer edge of said pin structure against said inwardly directed support shoulder; and   a bottom surface of said pin structure seated against said inwardly directed support shoulder,   said bottom surface of said pin structure also seated against said floor surface to support said pin structure against centrifugal loads in the presence of a centrifugal force field.   
     
     
       6. A centrifuge rotor assembly, comprising: a rotor yoke having a plurality of radially extending arms, the peripheral surface of the rotor yoke formed to define at least one longitudinal recess between each of the arms for receiving sample containers;   said rotor yoke further having a recessed upper surface that is coaxial with the axis of rotation of the rotor yoke, the upper surface defining, in each of the radially extending arms, a curvilinear inwardly directed support surface which is substantially parallel to the longitudinal recesses, so that the upper surface forms a substantially L-shaped surface in each of the radially extending arms;   a plurality of pin structures, each pin structure shaped to mate with the support surface of each radially extending arm, the pin structure having a mounting pin extending into each longitudinal recess formed between each of said radially extending arms;   each pin structure mounted upon the support surface of a radially extending arm, for mating with the support surface;   a plurality of trunnion rings, each ring having a set of oppositely disposed bores defined along their outer surfaces, so that each trunnion ring may be permanently mounted between opposing pin structures of adjacent radially extending arms of the rotor yoke.   
     
     
       7. The centrifuge rotor assembly of claim 6 wherein the rotor yoke is of a light weight first material and the pin structures are of a massive and strong second material. 
     
     
       8. The centrifuge assembly of claim 7 wherein the rotor yoke is of aluminum and the pin structures are of titanium. 
     
     
       9. The centrifuge rotor assembly of claim 6 wherein the pin structure comprises a slightly curved surface which is adapted to mate with the curvilinear inwardly directed support surface on each of the rotor arms; the pin structure having an outer surface that has a curvature that is a function of the circular recess of said rotor yoke and the inwardly directed support surfaces of each arm, so that the pin structures may be mated to each of the rotor arms to absorb all the outwardly directed forces generated by a sample and sample container when a centrifugal force field is generated by spinning said rotor yoke;   each of the pin structures being fastened to each of the rotor arms through a radially directed bore through the rotor arm and the pin structure by a fastening means which is not required to absorb centrifugal forces effecting the rotor yoke structure and the sample containers.   
     
     
       10. The centrifuge rotor assembly of claim 6 wherein each of the trunnion rings comprises: a generally cylindrical body which defines wide walls and a central bore coaxially through the trunnion ring for receiving sample containers;   a pair of pin-receiving bores formed through the side walls of the trunnion in an opposing and aligned relationship;   expanded wall portions surrounding the pin-receiving bores for additional strength, the trunnion body being tapered along said expanded walls forming a pair of circular end surfaces each with a wide chamfer adjacent the central bore, providing a loading surface for the sample container of minimum contact and stress between trunnion and container.